My ex has mental health issues. He hasnt seen our children in 6 months as I cut contact as the last time we spoke he said he was better and couldnt see them due to work. We cut contact after an argument and I didnt hear anything for 6 months. A few days ago he showed up at my door. I let him in and it became clear that he was still mentally unwell. He spent the entire time speaking about himself. I asked him to leave and have left it at that. I messaged him asking him not to contact me again. Aibu? According to some I should be trying to help him but I dont feel this is my responsibility as we are no longer together. He is my ex and not my problem.